Now, experts say a tiny mouse could hold the key to explaining all those love handles; it's medicine's next big thing.
Lisa Bohner has one wish.
"To have life again, to be normal," Bohner said.
She and her 455 pounds struggle every step, every day.
"Right now, I'm sorry, I only merely exist," Bohner said.
But this nearly quarter-ton woman may share a genetic link with a one-ounce mouse.
"It's a way that we can illustrate using mouse models with specific genetic characteristics to dissect these processes that are so common in the human population," said Dr. Philip Wood, professor at Sanford-Burnham Medical Research Institute at Lake Nona, in Orlando, Fla., explained.
Dr. Wood created six mouse models in his lab, and then inactivated different fat-burning genes in each one. It's a process called "gene targeting." Some got fat. Others built up insulin resistance. Others stayed healthy.
Now, he's matching each mouse with a two-footed counterpart -- a person with the same genetic make-up.
"We can sort of find the tipping point if you will," Dr. Wood said. "When does obesity show up? When does diabetes show up? When does high blood pressure show up?"
The goal is to indentify people whose genes pre-dispose them to being fat -- and all the diseases that follow and find therapies to turn off those switches.
"And the idea is that we're then beginning to put together the pieces to eventually pursue an individualized medicine for the average obese diabetic individual that comes in," Dr. Wood said.
Dr. Wood says in the average obese person, diet, exercise and environment make up half of the picture, and genetics controls the rest.
"I don't ask for any miracles," Bohner said.
Not a miracle but a genetic breakthrough that one day could lift her 455 pound burden.
Dr. Wood says he hopes to use the same mouse models that match human genotypes to test new drugs. He says it would greatly improve the success rate of developing new medicine.